Motion-checking device



Feb; 5 1924. 1,482,917

J. H. DURNO MOTION CHECKING DEVICE Filed July 17 [1922 uvwsmog B I, I ib' nroxmzy Patented Feb. 5, 1924.

- a STATES JOHN H. DURNO, or aoonnsrnn, NEW YORK.

MOTION-CHECKING DEVICE.

Application filed July 17, 1922. Serial No. 575,497.

To all whom-it may concern:

Be it known that 1, JOHN H. Dunno, a citizen of the United States of America, residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in M0- tion-Checking Devices, of which the following is a specification.

My invention relates to adoor check or device for retarding or cushioning the move ment of one element relatively to another, and it has for its purpose to afford a practical and economical construction that can be readily applied to a door or other similar part to be controlled.

A further purpose of the invention is to provide a construction involving but few parts, and which when once set up will continue indefinitely to function properly, eliminating likelihood of breakage or derangement of parts or the necessity of frequent adjustment.

Still tin-additional object of the invention is to provide a door check which depends for its operation upon the action of liquid,

such as oil, and which at the same time requires no valves, and but a. small amount of liquid.

- The invention also includes certain other advantages and improvements, all of which will appear clearly from the followingdescription in conjunction with the accompanying drawing, the novel features being pointed out in the claims following the description.

In the drawingz Figure l is a front'elevation showing the application of a preferred embodiment of the invention to a screen door and door frame;

Figure 2 is a plan view showing in full lines the'position of the parts when the door is closed, and in dotted lines the position of the parts when the door is open;

Figure 3 is a longitudinal sectional view through the cylinder constituting part of the mechanism, and

Figure 4: is a transverse sectional view on line t-A- of Figure 3.

i in the structure which I am about to describe, the details and specific arrangement do not limit the broad features of the invention, and the illustrated embodiment is intended only byway of example of various possible practical adaptations of my improvement.

The structure shown comprises in general In the operationof the mechanism, the

cylinder and piston-rod occupy a horizontal or approximately horizontal position, as shown, although one end may be tilted slight- 1y with reference to the other without disturbing the proper functioning of the parts. In this operative position, the bent end por tion 8 of the piston-rod extends downwardly and thus by its connection with the plate 9 serves to prevent rotation of the piston 5 within the cylinder. Said piston 5 is pro vided with a reduced opening 11 extending entirely therethrough and located preferably at a point beneath the center of the piston. I have illustrated the opening 11' as arranged near to the bottom of the piston, while 12 indicates a body of oil or other similar suitable liquid located in the bottom of the cylinder. I have found that excellent results are accomplished by having just enough liquid to approximately cover the opening I the door to closed position after it has been opened. a

By providing the stufiing-box 7, the cylinder 12 is made practically air-tight, and

there is no opportunity for the air within the cylinder to escape. Under these conditions, as the piston is moved in one direction or the other along the cylinder, it acts first to compress the air imprisoned in front of it, and this compressed body of air acting downwardly upon'the body of liquid at the bottom of the cylinder, holds said liquid evenly against the bottom of the cylinder and thereby causes the latter to move through the opening 11. By employing liquid such as oil for the checking medium, I obtain a steady and efiicient cushioning action, and by reducing the amount of liquid to a minimum, I reduce to a minimum the time required for the checking action. Thus the total time consumed in closing a door is considerably less than with known types of liquid checking devices where large bodies of liquid are required to pass through an opening, and at the same time I eliminate the disadvantages of checking devices which depend entirely upon air, while retaining the desirable quick action of the air, by utilizing it as the intermediary to force the liquid through the opening.

While I have described the invention with reference to a particular means, it is not limited or intended to be limited to this embodiment, but may be modified in various Ways without departing from the fundamental spirit of the improvement or the scope of the following claims.

I claim:

1. The combination with a cylinder attachable to one of a pair of relatively movable elements and arranged in approximately horizontal position when in operation, of a piston movable in the cylinder and provided with a free opening near the bottom thereof, a piston-rod carrying said piston and attachable to the other of said pair of relatively movable elements, and a relatively small body of liquid in said cylinder, said opening in the piston permitting flow of said liquid in either direction through the piston whereby the liquid passes to opposite sides of the piston only through said openmg.

2. The combination with a cylinder attachable to one of a pair of relatively movable elements and arranged in approximately horizontal position when in operation, of a piston movable in the cylinder and provided with a free opening near the bottom thereof, a piston-rod carrying said piston and attachable to the other of said pair of relatively movable elements, and a body of liquid arranged at the bottom of said cylinder and extending to a point approximately slightly above the top of said opening in the piston, said opening in the piston permitting flow of said liquid in either direction through the piston whereby the liquid passes to opposite sides of the piston only through said opening.

3. The combination with a cylinder attachable to one of a pair of relatively movable elements and arranged in approximately horizontal position when in operation, of a piston movable in the cylinder, a piston-rod carrying said iston and attachable to the other of said relatively movable elements, and a relatively small body of liquid in the bottom of said cylinder, the piston having a free opening beneath the level of said body of liquid, said opening in the piston permitting flow of said liquid in either direction through the piston whereby the liquid passes to opposite sides of the piston only through said opening.

4. The combination with a cylinder attachable to one of a pair of relatively movable elements and arranged in approximately horizontal position when in operation, of a piston movable in the cylinder and provided with a free opening beneath the center thereof, a piston-rod carrying said piston and attachable to the other of said pair of relatively movable elements, and a relatively small body of liquid movable back and forth through said opening along the bottom of the cylinder, said opening in the piston permitting flow of said liquid in either direction through the piston whereby the liquid passes to oppositesides of the piston only through said opening.

5. The combination with a cylinder attachableito one of a pair of relatively movable elements and arranged in approximately horizontal position when in operation,-of a piston movable in the cylinder, a piston-rod carrying said piston and attachable to the other of said relatively movable elements, a stufiing-box through which said piston-rod passes affording a substantially air-tight cylinder, the piston having a free opening, and a body of liquid movable back and forth through said opening, said opening in the piston ermitting flow of said liquid in either direction through the piston whereby the liquid passes to opposite sides of the piston only through saidopening.

6. The combination with a cylinder at tachable to one of a pair of relatively movable elements and arranged in approximately horizontal position when in operation, of a piston movable in the cylinder, a piston-rod carrying said piston and attachable to the other of said relatively movable elements, a stuffing-box through which said piston-rod passes affording a substantially air-tight cylinder, the piston having a free opening near the bottom thereof, and a relatively small body of liquid at the bottom of the cylinder movable back and forth through said opening, said opening in the piston permitt-ing flow of said liquid in either direction through the piston whereby the liquid passes to opposite sides of the piston only through said opening.

In witness whereof, I have hereunto signed my name. 1

JOHN H.- DURNO. 

